Rotary engine.



H. I. GROMBR.

ROTARY ENGINE.

APPLICATION FILED JULY 31, 1911, RENEWED MAY 19, 1913.

1, 1 21,866, Patented Dec. 22, 1914.

'7 SHEETS-SHEET 1.

z/rgj 5 THE NORRIS PETERS C D, F'HDTOYLITHQ, WASHINGTON, D LI,

H. I. GROMER.

ROTARY ENGINE.

APPLICATION FILED JULY 31,1911. RENEWED MAY 19,1913. 1,1 21,806.

Patented Dec. 22, 1914.

1 SHEETS-SHEET 2.

THE NORRIL PETERS ca, PHDTO LITHO- WASHING ION. D. t

H. I. CROMER.

ROTARY ENGINE.

APPLICATION TILED JULY 31, 1911. RENEWED MAY 19, 1913.

THE NORRIS PETERS CO-. PHOTO-LITHQ, WASHINGTON. D. C.

H. I. UROMER.

ROTARY ENGINE.

APPLICATION FILED JULY 31, 1911. RENEWED MAY 19, 1913.

1,121,806. Patented Dec.22,1914-.

1 SHEETS-SHEET4.

THE NORRIS PETERS CO. PHOTO-LITHQ. WASHING I'DN D. Q

H'. I. CROMEE.

ROTARY ENGINE.

APPLICATION FILED 1111131, 1911. RENEWED MAY 19, 1913. 1,1 21,806.

Patented Dec. 22, 1914.

7 SHEETS-SHEET 5.

' H. I. GROMEE.

ROTARY ENGINE. LLLLLLLLLLLLLLLLLLLL 31,1911. RENEWED MAY 19,1913.

1,121,806. Patented Dec. 22,1914.

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UNIT

HARRY IRWIN CROIVIER, 0F OAK PARK, ILLINOIS.

ROTARY ENGINE.

Application filed July 31, 1911, Serial No. 641,441. Renewed Play 18, 1913.

To all whom it may concern Be it known that I, HARRY IRWIN CROMER, a citizen of the United States, residing in Oak Park, in thecounty of Cook and State of Illinois, have invented certain new and useful Improvements in Rotary Engines and Mechanical Movements Adapted to Form a Part Thereof, of which the following is a specification.

My invention relates to that class of rotary engines, motors, compressors, pumps, or similar mechanisms, having rotary alternating pistons, and particularly to the means of operatively connecting the pistons in the proper relation to each other, and with a driven or driving shaft having its axis in a different plane or eccentric with the axes of the pistons.

The principal object of the invention is to provide a simple, economical and efficient rotary engine, compressor, pump, motor, or similar mechanism having rotary alternating pistons adapted to rotate upon the same axis, with means for operatively connecting the pistons in such a manner that an explosion, a compression, an intake or charge, and an exhaust will be caused to occur simultaneously, each in separate chambers in the same casing or cylinder and four times for each rotation of the pistons when the engine is used as an internal combustion engine, all without the use of gears, or reciprocating elements of any description for operatively connecting the pistons with each other, or with the shaft or shafts for driving the pistons, or to be driven thereby, and to enable all reciprocating elements and toothed gears for connecting the pistons with the driving or driven shaft to be dispensed with, and also to enable all valves to be dispensed with, and all valve operating parts, reciprocating or otherwise.

A further object is to provide an engine of the class described adapted to enable two charges of steam to be admitted simultaneously into separate chambers in the same casing, and two charges of steam to be exhausted simultaneously with the admission of the first mentioned plurality of charges of steam, and to provide means for adjusting the inlet and outlet openings to different positions.

A further object is to provide means for connecting the outlet passage or passages with the source of fluid supply and simultaneously disconnecting the inlet passages Specification of Letters Patent.

Patented Dec. 22,1314.

Serial No. 768,682.

from the source of fluid supply, and vice versa as desired, for the purpose of reversing the engine, or enabling it to be operated in opposite directions successively.

A further object is to provide an engine having rotary alternating pistons adapted to rotate about the same axis and having one or more driving shafts, the axis or axes of which are in a different plane from the axes of the pistons, with means for connecting the engine shaft or driven shaft directly with a traction wheel or wheels, propeller, or other elements to be operated thereby;

Other and further objects will appear from an examination of the drawings and the following description and claims.

The invention consists in the features, combinations and details of construction herein described, and claimed.

In the drawings, Figure 1, is a view in central sectional elevation of an engine constructed in accordance with my improve ments, and provided with inlet and outlet openings adapted to enable it to be operated by means of steam ;taken on line 1, of Fig. 17 Fig. 2, a plan view of the engine shown in Fig. 1, provided with inlet and outlet openings and a spark plug, adapted to enable it to be operated by means of combustible or explosive fluid,or an internal combustion engine; Fig. 3, a view in central sectional elevation of a two cylinder engine mounted upon a vehicle to be operated thereby, and provided with means for connecting the engine shafts directly with the traction wheels; Fig. 4, a central longitudinal sectional view in elevation of my improved mechanical movement, or crank and cam mechanism, showing it as applied to a compound engine, or engine and compressor: Fig. 5, a transverse sectional view, taken on line 5 of Fig. 1, with the pistons and crank and cam mechanism in the position they occupy when the engine is on a dead center or point of highest compression F i 6, a similar view taken substantially on line 6, of Fig. 3, looking in the direction of the arrow, and showing the pistons and crank and cam mechanism in the position they occupy at the time of the explosion, or beginning of expansion, or immediately thereafter; Fig. 7, a transverse sectional view taken on line 5 of Fig. 1., showing the pistons and crank and cam mechanism in the position they would occupy after rotating from the position shown in Fig. 7 to the positions shown in Figs. 6, 8, and 7 successively; Fig. 8, a view in transverse sectional elevation, taken substantially on line 8, Fig. 4, with one side of the casing removed, showing the position of the pistons, crank and cam mechanism and steam inlet and outlet openings, during the latter part of a stroke; Fig. 9, a view in transverse sectional elevation taken on line 9 of Fig. 2; Fig. 10, a transverse view in sectional elevation, taken on line 10, of Fig. 3, with one side of the casing removed and with parts of the frame omitted; Fig. 11, a transverse vertical sectional view taken substantially on line 11 of Fig. 1, with one side of the casing removed, showing the engine adapted to be operated by steam; Fig. 12, a transverse view in vertical section, taken substantially on line 12 of Fig. 1, with one side of the casing removed and showing the location of the inlet and outlet openings for steam and the means for connecting the outlet opening with the source of steam supply, and disconnecting it therefrom; Fig. 13, a detail view in transverse vertical section, taken on line 13 of Fig. 2, with one side of the casing removed; Fig. 14L, a similar View taken on the same sectional line and showing a different position of the inlet and outlet openings; Fig. 15, a similar view taken on line 15 of Fig. 2, with the pistons in the same position in which they are shown in Fig. 13, but with different inlet and outlet openings in full view; Fig. 16, a similar transverse vertical sectional view, taken on line 15 of Fig. 2, and showing the pistons in the same position in which they are shown in Fig. 1 1, but with different inlet and outlet openings in full view; Fig. 17 a transverse sectional view, taken on line 17, of Fig. 1, with one side of the casing removed; Fig. 18, a transverse vertical sectional view taken on line 18, of Fig. 1, with the pistons in the same position in which they are shown in Fig. 17, but with different inlet and outlet openings in full view; Fig. 19, a transverse vertical sectional view on line 17 of Fig. 1, with one side of the casing removed, and Fig. 20, a transverse vertical sectional view on line 18, of Fig. 1, showing the pistons in the same position in which they are shown in Fig. 19, but with different inlet and outlet openings in full view.

In constructing an engine in accordance with my improvements, 1 provide a stationary main frame or base a, (see Figs. 1, 2, 5, 6, 7 and 8). Rotary alternating pistons 01' and are provided, each having a pair of piston wings on opposite sides of their axial centers, and having a crank pin for each piston wing connected with said pistons, respectively, said crank pins being located on opposite sides of the axis of the piston with which they are connected and being coniected with the respective pistons either directly or indirectly but preferably by means of the shaft and sleeve and crank arm mechanism, as hereinafter described, the construction and arrangement of the piston mechanism and cranks and crank pins being, by preference, as follows: Mounted in suit able bearings in the stationary main frame is a shaft Z), and encircling the shaft 6 is a sleeve 0. Mounted upon and in fixed relation to the sleeve 0 is a piston cl having two radial wings e thereon; and mounted upon and in fixed relation to the shaft 1) is a piston having two radial wings g thereon. The wings of the piston d extend across the hub of the piston f, and the wings of the piston f extend across the hub of the piston (Z. Piston cylinder wall portions forming piston chambers or piston chamber portions into which the pistons or piston wings eX- tend are provided, preferably in the form of a single casing or cylinder and may be so mounted as to be connected either with a stationary base or support or freely rotatable with the pistons. The piston chamber r cylinder wall portions are adapted to be connected with the piston mechanism so as to be rotatable therewith or form a part thereof. A suitable casing for inclosing or admitting the piston wings, so as to form suitable piston chambers, is constructed as follows: Encircling and inclosing or forming piston chambers for the pistons (Z and or the radial piston wing portions of said pistons are piston cylinder wall portions which may be in the form of a casing or piston cylinder it having a hub portion 71 and forming with the piston wings four piston chambers or chamber portions. Mounted upon the sleeve 0, and in fixed relation thereto, is a double crank or pair of rigidly connected cranks j, each having a crank pin 70, on opposite sides of the axis of the sleeve. lvlounted in fixed relation to the piston and preferably upon and in fixed relation to the shaft Z) is a similar double crank or rigidly connected cranks Z, having crank pins m on diametrically opposite sides of the axis of said shaft, the crank pins or wrist pins and on all being the same distance from the axis of rotation, and all rotating upon the same axis. The positions of the wrist pins 70 may correspond with the piston wings 0, which are mounted upon the same sleeve, and the positions of the wrist pins m correspond with the positions of the piston wings 9 upon the same shaft. A main driving or driven shaft a is mounted in suitable bearings 0 and p in the main frame in such a position that its aXis is in a different plane from that of the shaft 6 and sleeve 0, and all of said axes are parallel. Mounted upon and in fined relation to the shaft n, is a cam having three sections of identical form and provided with three slots at equal distances from each other and converging toward the center of the. cam, but which slots need not actually meet though they may, for convenience in construction, be so made as to meet. These slots are preferably radial and divide the cam into three substantially equal portions forming cam surfaces between which the wrist pins is and m are adapted to move. The distance from the axial centers of the cranks to the wrist pins is greater than the distance from the axial center of the shaft 1?, to the axial cen ters of the cranks and shaft and sleeve upon which the cranks are mounted, and the cranks and cam are mounted in such position that the rotation of the cranks will cause each of the crank pins to move into a different slot in the cam with each revolution of the crank pin. In other words, there is at least one more crank pin than there are slots in the cam, and each of the crank pins moves around the axial center of the cam, and each time a crank pin moves around the center of the cam it engages a different slot and is engaged by different converging or radial cam surfaces. All of the crank pins, piston wings and slots or cam surfaces rotate in the same direction, and each crank pin turns upon an axis which is eccentric to the axis of the cam and the shaft upon which the cam is mounted and moves around the axis of the cam; and with each rotation around the axis of the cam each crank pin or wrist pin moves into a diflerent slot in the cam-the slot immediately back of the slot from which said pin last emerges. The cam is provided with cam surface portions .9 on opposite sides of each slot near the periphery of the cam or ends of the respective slots which curve outward radially of the cam and inward toward the center of the respective slots so as to engage each crank pin successively as shown on the left side of Fig. 8, where the upper crank pin k is engaged by one of said cam portions .9. The conformation of the cam portion 8 is such that whenever an outwardly moving crank pin engages it while turning the cam, the cam is thereby rotated with respect to the crank pin on the opposite end of the same double crank in such a manner that the latter crank pin, as it moves inward, will operatively en age the cam before the upper crank pin which is in engagement with the cam portion .9 becomes disengaged from the cam. The inwardly moving crank pin will be caused to move inward before coming in contact with the cam, in a direction substantially toward the center of the moving cam, and in a direction which is substantially identical with the direction of move ment of the inwardly moving crank pin at the time of, and immediately after, coming in contact with the cam. At least one crank pin or one double crank, or in other words, one of the two crank pins operatively connected with each piston, is thus at all times in operative engagement with the cam, and the desired position of the pistons with respect to each other is at all times maintained by the cam and crank mechanism in a positive and efficient manner, and the pins engage and disengage with the cam with as little jarring as possible.

By connecting the shaft n with a suitable source of power, which may be accomplished by a pulley t, or by means of any suitable connecting mechanism, and by driving the shaft n and thereby the cam g, the cranks and pistons will be rotated from the position shown in Fig. 5 to the position shown in Fig. 6, and thence to the position shown in Fig. 8, and thence to the position shown in Fig. 7, and so on. By applying power to the pistons by means of the expansion of compressible fluid, such as gas, steam, air, or other suitable fluid, the pistons drive the cranks and crank pins and thereby the cam q and shaft n and any mechanism with which the shaft 41 is connected.

In order to enable the pistons to operate upon or to be operated by means of steam, air, gas, or other fluid under compression or compressible fluid, suitable fluid inlet pipes u and o, are provided and connected with a suitable source of steam or other fluid supply by means of a main feed pipe to (see Figs. 1, 4t, 11, 12 and 17 to 20 inclusive). There may be two of the pipes to, one communicating with an inlet opening or port 2, in an annular port member or casing portion a on one side of the cylinder, and the other with an inlet port 3 in a similar port member or casing portion 4} on the opposite side of the cylinder, and each of which ports are adapted to communicate with the respective chambers between the piston wings through the openings 5 in the hub of the piston 61 and the openings 6 in the hub of the piston f on opposite sides of the cylinder alternately. (See Figs. 1, 17, 18, 19 and 20). There may also be two of the lower inlet pipes 1; arranged in a similar manner on opposite sides of the cylinder and adapted to communicate with the same passages 5 and 6 alternately on opposite sides of the cylinder, through inlet ports 9 in the port members a and 4.

A plurality of pipes 7 and 8, (see Figs. 4:, 11, and 12, and 17 to 20 inclusive) adapted to serve as outlet pipes, are provided, as shown in said figures and in Figs. 1 and 2, said pipes being arranged directly opposite to each other and on opposite sides of the cylinder or casing h, or each of a plurality of casings or cylinders, in position to com municate through ports 10 in the port members or casing members 2 and 4 respectively. with the passages 5 and 6 in the piston members, on opposite sides of the cylinder or casing member or members or sets of pistons alternately, as indicated in Fig. 11, and Figs.

17 to 20 inclusive, all in such a manner as to permit steam, air or other compressible fluid to exhaust from two chambers in each cylinder or casing, while steam, air or other motive fluid is being admitted through the inlet pipes into two other chambers in the same cylinder or casing, as already suggested.

In order to provide means for enabling the cylinder or casing, and thereby the spark 21 in the portion of the cylinder which is passed by the piston wings, and which forms or corresponds with the location of the explosion chamber, to be adjusted with respect to the plane in which the axes of the pistons and cranks and cam mechanism and cam shaft or main driven shaft are located, and with respect to the point at which the fluid is located when under the highest degree of compression, so as to enable the spark plug and the ignition port in which it is mounted to communicate with the explosion chamber at different points with respect to the plane in which the axes of the pistons and the cam or driven shaft are located, for the purpose of advancing or retarding the spark and changing the positions of the inlet and outlet openings by rotating or partially rotating the cylinder or casing to any desired position, I provide a screw 34 for each cylinder, and mount it on an operating shaft 35, supported in suitable bearings 36, and held against movement transversely of the engine by means of collars 37, and mount each of said screws in toothed engagement with a toothed member or portion 38 of each cylinder respectively. The cylinder may be partially rotated or adjusted to any desired position, and the spark plug 21 and inlet and outlet openings of the cylinder of either an engine fitted for compression or fitted with inlet and outlet ports for steam or air, may be readily adjusted by rotating the worms or screws by means of operating wheels 38 on each worm shaft. A similar screw 42 on a commutator operating shaft 41, operatively connected with the commutator by means of a lever arm 43 thereon, and having an arm 89 on the shaft 11, is adapted to be operated simultaneously with the worms 34, by connecting all of the worm-shaft levers 39 by means of connecting and operating rod 40. By this means the cylinder or cylinders with their spark plugs, and the commutator may be operated synchronously. The rod L0 is adapted to be connected with and operated by a governor operating with the main engine shaft, to automatically advance and retard the spark and ports,

The engine constructed in accordance with my invention,both when adapted to be used as an internal combustion engine or with a compression chamber, and when adapted to be used as a steam engine, or to produce two simultaneous admissions and two simultaneous exhausts-may be constructed with the casing, cylinder or cylinders stationary, or integral with the stationary base, or rotatably mounted, with a stationary base or main frame (as shown in Figs. 1 and 2), or so mounted as to be ad; justable by rotation or partial rotation, and provided with means for holding the casing or cylinder stationary in any position to which it has been adjusted, (as shown in Figs. 1, 8, l, 6, 8, 9, 10, 1.1 and 12,) or so mounted as to be capable of adjustment by rotation or partial rotation for regulating the ignition or the inlet and outlet ports when desired, and adapted to be permitted to rotate when desired, or to beheld stationary in any desired adjusted position, as shown in Figs. 1, 2, 8, at the right and left ends of Fig. 4:, and in Figs. 5, 6, 7, 9, and 11. By mounting the casing, cylinder or cylinders either stationary upon or integral with the base, or in such a manner as to be adjustable by rotation or partial rotation, and held stationary in any desired adjusted position, and providing each cylinder, or piston inclosing casing portion with suitable inlet and outlet ports beyond the hub portions of the inclosed pistons in the direction of or at the periphery of the casing or cylinder, (as shown in the central portion of Figs. 4r, 8, 10 and 12, or in either of said figures) the port members 2 and t and their ports, and the port members 11 and 12 and their ports, and the passages 5 and 6 in the pistons may be plugged up or dis aensed with, and the engine will be adapted to 0p crate in either direction,forward or backward upon changing the inlet or inlets to outlets, and connecting the outlet or outlets with a source of combustible or expansive fluid supply.

The engine embodying my invention, as shown in Figs. 3, 6, and 10, is constructed in all respects in accordance with the foregoing description in connection with Figs. 1, 2, 5, 9, 13 and 15, ith the port members 2 and t of Fig. 1 and 11 and 12 of Fig. 2, and the passage 5 and 6 in the pistons omitted, with the exception of the differences, features, elements and parts hereinafter described or illustrated in the drawings. There are two complete sets of shafts Z), sleeves c, pistons d and f with passages 5 and 6 in the pistons omitted, cranks and Z, crank pins and m, shafts n and cam members 9*, all constructed and adapted to operate substantially as above described. A casing or cylinder 60 incloses each pair of pistons (Z and f, and is formed of two annular casing portions or heads each provided with an axial opening or recess for admitting the shaft 5, and one or both of which cylinder portions are provided with means for supporting the cylinder in such a manner that it can be rotated or partially rotated or adjusted, and held stationary in any desired position to which it is adapted to be adjusted, the casing members being secured together in any desired manner, as by means of bolts 61 in their flanged portions. In order to provide suitable means for supporting and permitting the adjustment or rotation of the cylinder or cylinders as above suggested, each cylinder is provided with a hub or projecting portion 62.

on one or both sides thereof mounted in a suitable stationary support or main frame 63 in suitable bearings or sockets 65, in pillars or frame portions 66, and, for holding the casing stationary in any position to which it is adjusted, bearing members or clamps 67 are secured to the stationary or main frame by means of bolts,not shown in such a manner as to enable the bearing members 67 to be clamped or secured in clamping engagement with the hub portion of the cylinder. Each cylinder or casing is provided with an inlet port 44 (see Fig. 10)

; in the casing portion beyond the piston hub,

in the direction of or in the periphery of the casing and adapted to be opened and closed by the piston wings as they pass the port, said inlet port being connected with a source of fluid supply, such as the carbureter 19 by means of a supply pipe 45 which com1nunicates with said port and carbureter. Each cylinder or casing is also provided with an outlet port 46, also in the casing portion which is beyond the piston hub, in the direction of or in the periphery of the casing and in position to be opened and closed by the piston wings as they pass said port successively. Each casing or cylinder is also provided with a spark plug 21 extending into an ignition port 68 which is located in position to communicate with the explosion chamber between the piston wings, when the wings are in position to produce the high- I est compression, or immediately before or after the highest point of compression is reached. The main frame shown in Fig. 3 is adapted to form a part of the frame of a vehicle, which may be of any form or type, such, for instance, as an automobile, boat or flying machine, and is here shown as forming a part of theframe or axle of an automobile or traction vehicle, said frame being provided with an upper frame member 69 forming the upper chord of a truss, the

lower chord of which is formed by the base of the frame. The upper and lower chords may be connected by means of the uprights or pillars 66 secured in position in any desired ordinary and well known manner of connecting such elements. The main frame is provided at each end with pillars 70 in which the shafts n are supported in suitable bearings, and in position to extend into and concentric with the hubs of the vehicle wheels 71 of the vehicle, and to be connected directly with the latter. The shafts n are adapted to form a support for or to be supported by any element with which they are connected, but are here shown supported independently of the vehicle wheels, butadapted to be connected directly with the wheels when desired, and also to be connected with the vehicle Wheels indirectly or through the medium of gears for varying the speed of the vehicle with respect to the speed of the engine, and with differential gear mechanism, as desired. The casing or main frame is provided with a chamber 72, at each end of the frame or each side of the vehicle, through which the shafts n extend, and a spindle 73 formed by or mounted on the frame extends into engagement with the hub 74 of each wheel 71 in position to support or be supported by the latter. The hubs are each provided with recesses 75 in their axial openings adapted to receive splines 76 on transmission gear wheels 77 and slidably' mounted in slots 78 in the respective shafts 'n. A differential gear is provided which may be of any ordinary or well known form of diflerential gear wheels, and has a casing 79 provided with tubular casing portions 80 which extend into the gear chambers 7 2. On these tubular differential gear casing portions are mounted, a friction gear wheel 81, and spur gear wheels 82 and 83, all in fixed relation to the differential gear casing or tubular members of the diflerential gear. There is a friction gear wheel 84 slidabl mounted on and rotatable with the shaft 1% and adapted to be moved longitudinally of the shaft into and out of frictional engagement with the gear wheel 81; and the transmission gear wheel 77 is movable into and out of toothed engagement with the wheels 82 and 83 respectively, the connection with the wheel 82 being for reverse and the connection with the wheel 83 being forward movement, and the friction wheels being also adapted to cause forward movement of the vehicle. Operating levers 85 are for operating the transmission gear wheels 7 7, to move them into and out of toothed engagement with the spur gear wheels 82 and 83, and to move the clutch or spline members of the wheels 77 into and out of engagement with the vehicle wheels or hubs, or similar elements to be operated by the engine through the medium of the shaft n. A direct connection between the shafts n and the hubs of the wheels 71 can thus be made, and the shafts it left free to revolve without carrying any of the weight of the load upon the vehicle. Mounted on the opposite ends of and in fixed relation to the inner shafts 86 of the differential gear mechanism is a pair of spur gear Wheels 87 each in toothed engagement with a spur gear wheel 88 on the hub of the corresponding vehicle wheel 71. The shafts 86, being connected in the ordinary manner by the differential gear wheels-not shown-and by the casing members 79 and 80, thus form a connection between the vehicle wheels 71 whereby their speed with respect to each other is governed. The engines being connected with the respective vehicle wheels, when operating the latter, are also operatively connected through the medium of the difierential gear mechanism above described. The transmission gear mechanism may be thrown out of operative engagement with the shafts n so as to permit the latter to rotate freely without engagement with either the transmission mechanism or the vehicle wheels, by moving the clutch or spline 76 out of engagement with the hub of the vehicle wheel and at the same time out of engagement with the gears 82, and 83. The shafts b of the engines shown in Fig. 3 may be connected so as to operate as one continuous shaft, and may be disconnected, as from each other as desired, by means of a clutch 89, which may be of any desired or known form, and is provided with an operating lever 90. In Fig. 3 the pistons and crank and cam mechanism of one cylinder or engine are in a different position from those of the other. It will be noted that this arrangement will result in the explosion in the different cylinders occurring at different t mes, thus overcoming the so called dead center, and cansing the engines to cooperate and run smoothly.

The engine embodying my invention, as shown in Figs. 1:, 8, and 12, comprises three engines or sets of pistons (Z, f, shafts Z), sleeves c, cranks and Z, crank pins and m, and shafts n all constructed and adapted to operate substantially as already describedthe engines or sets of said elements at the opposite ends of the figure each having port members 11 and 12 provided with ports adapted to communicate with the passages 5 and 6 in the pistons, and inlet and outlet pipes all substantially as described in connection with Fig. 1, and the engine or set of said elements at the central portion of the figure being without the port members 11 and 12 and the passages 5 and 6 in the pistons, and substantially as described in connection with Fig. 3. In all other respects the engine or engines there shown are constructed in accordance with the foregoing description in connection with Figs. 1, 2, 5, 8, 11, 12, and 17 to 20 inclusive or respectively, with the exception of the differences, features, elements and parts herein described or illustrated in the drawings.

The engine or set of engines shown in Fig. 1, and also in Figs. 8 and 12referring now particularly to the engine shown in the central part of Fig. -1is constructed as follows: It has a shaft Z), sleeve 0, pistons d and f, with passages 5 and 6 in the pistons omitted, cranks j and Z, crank pins 70 and m, and n and cam member g, the shaft 1) being connected with or adapted to form a part of a similar shaft 6 of the next adjacent unit, engine or set of pistons, cranks, cam mechanism, sleeve and shafts of similar or identical construction. For this purpose, a clutch 100 is provided, which may be of any desired, ordinary or well known form, and is adapted to be operated by means of an operating lever 101, to connect and disconnect the shaft b With the next adjacent shaft or similar member to be operated with or by means of the shaft 5. The casing 102 or cylinder is identical in construction with the casings 60 shown in Fig. 3, with the exception that the inlet and outlet ports are so arranged as to enable two charges to be admitted simultaneously and two exhausts to occur simultaneously in the casing 102. In order to accomplish this a plurality of inlet ports 50 are provided in the casing 102 at points outward radially from the hub of the piston in the direction of or at the periphery of the casing and in position to be passed by the piston wings, which wings have already been described in connection with Figs. 1, 2, and 3. And two outlet ports 51 are likewise provided in the casing 102 at points on directly opposite sides of the axial center of the casing or pistons and outward from the hub of the piston in the direction of or at the periphery of the easing, in position to be passed by the piston wings. These inlet openings are so located with respect to the piston wings and the plane in which the axes of the pistons and the cam mechanism are located, that they will at all times be separated from the exhaust chambers 103 by a piston wing, and the same is true of the inlet opening ea of the engine as illustrated in Figs. 3, 0, and

10. The outlet openings or ports 51 are so located that they will at all times be separated from the expansion chambers 10% by a piston wing, and will be opened by the movement of the wing which closes them beginning substantially with the beginning of the expansion and remaining open until all or nearly all of the exhaust fluid is permitted to escape. The same is true of the outlet port of the engine as illustrated in Figs. 3, 6, and 10. And the inlet ports li and 50 respectively are each so located that the piston wing by which they are closed begins to move away from said ports respectively substantially simultaneously with the beginning of a stroke or impulse or expansion causing the port or ports to open and remain open until the admission chamher is filled with fluid for driving the wings or operating the pistons, or to be operated upon thereby. In order to insure a perfect fit and proper compression or prevent leak- I main outlet age between the piston wings and the casing in which they are mounted, the wings are each provided with suitable packing strips 105, shown in Figs. 1 and 4:, said strips being adapted to extend flush with opposite surfaces of the piston wings respectively and to be separated slightly, the one on one side of the wing, from that on the other, and held yieldingly in engagement with the surface of the cylinder, and with the ports passed by the wings, as indicated in broken lines in the central portion of Fig. 1. They are thus held in yielding engagement by means of the springs 106, which may be of any desired suitable form and material.

The inlet ports are each provided with a branch supply pipe 107 which converge, as shown in Figs. 1 and 12, into a common pipe 108. The outlet ports 51 are each provided with a branch outlet pipe 109, which branch outlet pipes converge into a common pipe 110, and a two way cock 111, having passages 112 and 113 therethrough is interposed between the pipes 108 and 110 respectively and main inlet pipe to and the main outlet pipe 11-1, as shown in Fig. 12. By this arrangement, it will be seen that by turning the cock 111 to the position indicated in Fig. 12 the inlet ports will be connected with. the main inlet pipe '20, and the outlet port 51 with the main outlet pipe 114:, and by turning the cock from said position the pipe 108 and thereby the branch pipes 107 and the inlet ports 50 will be connected with the outlet pipe 114, and at the same time the pipe 110 and thereby the branch pipes 109 and the outlet ports 51, will be connected with the main inlet pipe 20, for the purpose of enabling the engine to be run backward or reversed. By means of the three way cock 115 at the intersection of the inlet pipe u of the cylinder to the left of cylinder 102, with the connecting pipe 116-the latter being connected with the pipe 114, as shown in Figs. 1 and 12, fluid from the exhaust chambers of the cylinder 102 may be condu ted through the inlet pipes to into the admission or expansion chambers of the cylinder 120. The cylinders 102 and 120 and the piston mechanism thereof being thus adapted to be used together as a compound compressor, in which case the cylinder 121 is adapted to serve as the engine for operating the com pressor, the cylinders 120 and 121 and their piston mechanism being substantially the same in construction and operation as to all of their parts as that shown in Fig. 1 and described in connection with said figure.

The only material ClllTGlGIl e being in the semi-circular form of the piston wings 122 in the cylinder 120, and the corresponding circular form in cross-section of the cylinder 120, as shown in Fig. 1, and the form of the packing strips 123, which, being substantially semi-circular, with straight inner end portions, are adapted to spring outward and yieldingly engage the inner surface or" the cylinder so as to form an efiicient packing, particularly when the latter is used as an internal combustion engine. The pack ing strips are of course, of metal, when the engine is to be so used. The three way cock 115 at the intersection of the outlet pipe 7 of the cylinder 120 with the main inlet or supply pipe w, shown in Fig. 4, is adapted to enable the outlet or exhaust chambers of the cylinder 120 to be connected with the inlet or supply pipes and inlet ports of the cylinder 102, when said cylinders and their piston mechanism is used as a compound engine, in which case the cylinder 121 and its piston mechanism is adapted to be used as a compressor or pump. (Jocks 117 in the main inlet pipe and 118 and 119 in the main discharge pipe 11% serve to connect the respective cylinders, engines or units with each other, or to separate them from each other, as desired.

1 claim:-

1. In a mechanism of the class described, the combination of a plurality of crank members rotatably mounted upon the same axis in movable relation to each other, a pair of crank pins connected with each of said crank members respectively and rotatable upon the same axis, and a cam member rotatably mounted eccentric to the crank members and having a plurality of slots converging toward its central portion and each movable into and out of engagement with each of a plurality of said crank pins successively.

2. In a mechanism of the class described, the combination of a plurality of crank members rotatably mounted upon the same axis in movable relation to each other, and each provided with a pair of crank pins at equal distances from and on opposite sides oi. its axial center, and an eccentric cam member extending between said crank pins and rotatable in the same direction therewith, said cam member having a plurality of slots converging toward its central portion and each adapted to receive each of a plurality of said crank pins successively.

3. 111 a mechanism of the class described, the combination of a plurality of crank members rotatably mounted upon the same axis in movable relation to each other, crank pins upon said crank members, a cam mem- "er rotatably mounted and having its axial center in a different plane from that in which the axis of the crank members is located, said cam member having a plurality of slot portions diverging toward its periphery, each of said crank pins being adapted to engage each of said diverging slot portions successively, and a shaft connected with the cam member.

4;. In a mechanism of the class described the combination of a plurality of crank members rotatably mounted upon the same axis in movable relation to each other, a pair of crank pins connected with each of said crank members respectively and rotatable upon the same axis, a cam member rotatably mounted with its axial center in a different plane from that in which the axis of the crank members is located, said cam member having a plurality of slots diverging toward its periphery and each adapted to receive and engage each of a plurality of said crank pins successively, a shaft connected with the cam member, and a shaft concentric with respect to and connected with one of the crank members.

5. In a mechanism of the class described, the combination of a plurality of crank members rotatably mounted upon the same axis in movable relation to each other, a pair of crank pins connected with each of said crank members respectively and rotatable upon the same axis, a shaft concentric with respect to and connected with one of the cam members a sleeve concentric and in movable relation to said snaft and con-- nected with the other crank, a shaft having its axial center in a different plane from that in which the axis of the crank members is located and having a plurality of slots diverging toward its periphery and each adapted to receive and engage each of a plurality of crank pins successively, and means for supporting said shafts and sleeve.

6. In a mechanism. of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other and each having con nected piston wings on opposite sides of its axial center, and provided with piston cylinder walls forming piston chamber portions into which the piston wing portions of the pistons extend, crank pin mechanism operatively connected with each piston and rotatable therewith, and cam mechanism rotatably mounted in engagement with the crank pin mechanism of both pistons and having its axial. center parallel to the axial center of the pistons.

7. In a mechanism of the class described, the combination of a plurality of concentric pistons rotatably mounted in movable relation to each other and each comprising a plurality of connected rotary piston wings intermediate the piston wings of the next adjacent piston, a cylinder inclosing the pi tons, crank pin mechanism operatively connected with each piston and rotatable therewith, and cam mechanism rotatably mounted in engagement with the crank pin mechanism of both pistons.

8. In a mechanism of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other and each having a pinrality of piston wings each intermediate the piston wings of the next adjacent piston, a cylinder in which the pistons are located, crank pin mechanism operatively connected with each piston and rotatable therewith, and cam mechanism extending between the crank pins and in engagement with the crank pin mechanism of both pistons, and having its axial center parallel with the axial center of the pistons.

9. In a mechanism of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other and each having piston wing portions on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a cylinder inclosing the pistons, a plurality of crank pins connected with each piston and rotatable with the latter, and cam mechanism rotatably mounted in engagement with the crank pin mechanism of both pistons.

10. In a mechanism of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a cylinder in which the pistons are located, a plurality of crank pins connected with each piston and rotatable with the latter, cam mechanism mounted in engagement with the crank pin mechanism of both pistons, and rotary shaft mechanism in fixed relation to the cam mechanism.

11. In a mechanism of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other, each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a cylinder in which the pistons are located, a plurality of crank pins connected with each piston and rotatable with the lat-- ter, rotary cam mechanism mounted in engagement with the crank pin mechanism of both pistons, rotary shaft mechanism connected with the cam mechanism and having its axial center in a different plane from the axial center of the pistons, and means for supporting said rotary shaft mechanism.

12. In a machine of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a cylinder in which the pistons are mounted, provided with inlet and outlet passages adapted to communicate with spaces between the piston wings, a series of crank pins, means for connecting a plurality of crank pins with each piston respectively, and cam mechanism rotatably mounted and adapted to engage the crank pin mechanism of both pistons.

13. In a machine of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet passages adapted to communicate with spaces between the piston wings, a plurality of crank pins connected with each piston respectively, and rotatable upon the same axis, and cam mechanism rotatably mounted and having a different axial center from that of the pistons and crank pin mechanism, and in engagement with the crank pin mechanism of both pistons.

14. In a machine of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet passages adapted to communicate with spaces between the piston wings, each of said passages being adjacent to the surface of and adapted to be opened and closed by the piston mechanism, a plurality of crank pins connected with each piston respectively and rotatable upon the same axis with the latter, and cam mechanism rotatably mounted in engagement with the crank pin mechanism of both pistons, said cam mechanism having a difi'erent axial center from that of the crank pin mechanism and pistons.

15. In a machine of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other, and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet ports adapted to communicate with the spaces between the piston wings, each of said ports being adjacent to the surface of and adapted to be opened and closed by a piston, a plurality of crank pins connected with each piston, respectively, cam mechanism rotatably mounted in engagement with the crank pin mechanism of both pistons, and having a different axial center from that of the pistons and crank pin mechanism, and rotary shaft mechanism connected and rotatable with the cam mechanism.

16. In a machine of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other, and each having piston wings on opposite sides of its axial center and intermediate the' piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet ports adapted to communicate with the spaces between the piston wings, a plurality of crank pins connected with each piston respectively and rotatable with the latter, and a cam member rotatably mounted on a different axial center from that oi? the pistons and crank pin mechanism, said cam member having slots diverging toward its periphery and each adapted to engage a plurality of said crank pins.

17. In a machine of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other, and each having piston wings on opposite sides of its axial center and in termediate the piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet ports adapted to communicate with different spaces between the piston wings, a plurality of crank pins connected with each piston respectively and rotatable with the latter, and a cam member rotatably mounted on a different axial center from that of the pistons and crank pin mechanism, said cam member having a plurality of slots diverging from its central portion toward its periphery and in engagement with the crank pin mechanism of both pistons.

18. In a machine of the class described, the combination of a plurality of concentric pistons rotatably mounted in movable relation to each other, and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet ports adapted to communicate with spaces between the piston wings, a plurality of crank pins connected with each piston respectively and rotatable with the latter, and a cam member rotatably mounted on a different axial center from that of the pistons and crank pin mechanism, and having a plurality of slots diverging from the central portion outward toward the periphery of the cam member and each adapted to engage a plurality of said crank pins successively.

19. In a machine of the class described,

' the combination of concentric rotary pistons mounted in movable relation to each other, and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet ports adapted to communicate with spaces between the piston wings, a plurality of crank pins connected with each piston respectively and rotatable with the latter, and a cam member rotatably mounted on a different axial center from that of the pistons and crank pin mechanism and in constant engagement with the crank pin mechanism of both pistons, said cam member having slot portions diverging outward from its central portion toward its periphery and each adapted to engage a plurality of said crank pins successively.

20. In a machine of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other, and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet ports adapted to communicate with spaces between the piston wings, a plurality of crank pins operatively connected with each piston respectively and rotatable with the latter, a cam member rotatably mounted on a' different axial center from that of the pistons and crank pin mechanism and in constant engagement with crank pin mechanism of both pistons, and a shaft upon which said cam member is mounted.

21. In a machine of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other, and each having piston wings on, opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet ports adjacent to and adapted to be opened and closed by the piston mechanism, a plurality of crank pins operatively connected with each piston respectively and rotatable with the latter, and a cam member rotatably mounted on a different axial center from that of the pistons and in constant engagement with the crank pin mechanism of both pistons, said cam member having a plurality of slot portions one lessin'number than there are crank pins, each of said slot portions diverging outward from the central portion of the cam toward the periphery of the latter and adapted to engage a plurality of the crank pins successively.

22. In a machine of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other, and each having piston Wings on opposite sides of its axial center and in termediate the piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet ports adjacent to and adapted to be opened and closed by the piston mechanism, a series of crank pins, a sleeve connected with one of said pistons and with a plurality of said crank pins, a shaft extending through said sleeve and connected with the other piston and with a plurality of different crank pins from those with which the sleeve is connected, and a cam member rotatably mounted ona, different axial center from that of the pistons and crank pin mechanism and in constant engagement with crank pin mechanism of both pistons.

23. In a machine of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other, and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet ports adapted to communicate with spaces between the piston wings, a shaft connected with one of said pistons, a plurality of crank pins located on opposite sides of said shaft and connected and rotatable with the shaft, a sleeve encircling said shaft and connected with the other piston, a plurality of crank pins located onopposite sides of the axis of said sleeve and connected and rotatable with the sleeve, and a cam member ro tatably mounted and having a different axial center from that of the pistons and crank pin mechanism, and in engagement with crank pin mechanism of both pistons.

24:. In a machine ofthe class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other and each having piston wings on oppositesides of its axial center and intermediate piston wings of the next adjacent piston, a cylinder encircling the pistons and providedv with inlet and outlet ports, a shaft connected with one of said pistons and rotatable with the latter, a plurality of crank pins located on opposite sides of the axis of the shaft, means for connecting said crank pins with the shaft, a sleeve encircling said shaft and connected and rotatable with the other piston, a plurality of crank pins located on opposite sides of the axis of the sleeve and shaft, and connected and rotatable with the sleeve, a cam member rotatably mounted and having a different axial center from that of the pistons and crank pin mechanism, and in engagement with the crank, pin mechanism of both pistons, said cam member having a plurality of slot portions one less innumber than there are crank pins, each, of said slot portions diverging outward from the central portion of the cam toward the periphery of the latter and adapted toengage a plurality of said crank pins successively, and a shaft upon which said cam member is mounted.

25. In a machine of the class described, the combination of a plurality of concentric rotary pistons mounted inmovable relation and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet ports, a pair of crank pins for each iston, means for connecting each piston with a pair of crank pins, the crank pins of each piston being in movable relation to the crank pins of the other piston, and a cam member mounted on a different axis from that of the pistons and crank pins and adapted to engage three of the crank pins while out of engagement with the fourth crank pin.

26. In a machine of the the combination of a plurality of concentric rotary pistons mounted in movable relation to each other and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet ports, a pair of crank pins for each piston, means for connecting each piston with a pair of crank pins, adapted to permit the crank pins of each piston to move with respect to the crank pins of the other piston, a cam member having its axial center on the inside of the path of movement of the crank pins, and having a plurality of slot portions diverging from the central portion of the cam member toward its periphery and in engagement with crank pin mechanism of both of said pistons, each of said diverging slot portions of the cam being adapted to engage a plurality of said crank pins successively, and a shaft upon which the cam member is mounted.

27. In a machine of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next ad jacent piston, a cylinder encircling the pistons and provided with inlet and outlet ports adapted to communicate with spaces between the piston wings, means for rotatably supporting said cylinder, a plurality of crank pins for each piston, means for connecting each piston with a pair of said crank pins, and a cam member rotatably mounted on a difierent axial center from that of the pistons and crank pin mechanism and in engagement with the crank pin mechanism of both pistons.

28. In a machine of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adj acent piston, a rotatable cylinder encircling the pistons and provided with inlet and outlet ports adapted to be opened and closed by the piston mechanism, crank pins for each piston, means for connecting each piston with a pair of said crank pins, a cam member rotatably mounted and having a diiferent axial center from that of the pistons and crank pin mechanism, and having a pluclass described,

-rality of slot portions diverging from the centralportion of the cam member toward its periphery and each adapted to engage a plurality of said crank pins successively, and a rotary shaft connected. and rotatable with the cam member. I i

29. In a machine of the class described, the combination of a plurality of concentric rotary piston mounted in movable relation to each other and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a rotatable cylinder encircling the pistons and provided with inlet and outlet ports adapted to communicate with the spaces between the piston wings, means for securing the cylinder in any desired position to which it is adapted to be rotated, a

pair of crank pins for each piston, means for connecting each piston with a pair of crank pins, a cam member rotatably mounted and having a different axial center from that of the pistons and crank pin mechanism, and having a plurality of slot portions diverging from the central portion of'said cam member and in engagement with crank pin mechanism of both pistons, and a shaft upon which said cam member is mounted.

v 30. In a machine of the class described, the combination of a plurality of concentric rotary pistons mounted in movable relation to each other and each having piston wings onvopposite sides of its axial center and intermediate the .piston wings of ,the next adjacent'pisto-n, a cylinder encircling the piston and provided with inlet and outlet ports, a pair'of crank pins for each piston, means for; connecting each piston with a' pair of crank pins, adapted to permit the movement of the crank pins of each piston with respect to those of the other piston and allupon the sameaxis, and a cam member having its axial center inside of the path of movement of all of said crank pins and on a different plane and parallel with the axial center of the pistons, said cam member having slotted portions in engagement with the crank pin mechanisinof both pistons.

31. In a machine of the class described, the combination of aplurality of concentric rotary pistons mounted in movable relation to each other and each having piston wings on opposite sides of its axial center and intermediate the piston wings of the next adjacent piston, a stationary base, a cylinder encircling the pistons and adjustably mounted in the stationary base, and provided with inlet and outlet ports adapted to communicate with the spaces between the piston wings, means for securing the cylinder in any position to which it is adapted to be adjusted, a pair of crank pins for each piston, means for connecting each piston with a pair of said crank pins, and a cam member rotatably mounted on a difi'erent axial center from that of the pistons and on opposite sides of its axial centerand intermediate the piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet port s adapted to communicate with the spaces between the piston wings, a pair of crank pins for each piston, means for connecting each piston with a pair of said crank pins, a cam member having three slots diverging from its central portion outward toward its periphery and each movable into and out of engagement with a plurality of said crank pins successively, said cam member being adapted to at all times engage crank pins of both pistons, and having a diiferent axis from that of the pistons, and a shaft upon which the cam member is mounted.

33. In a machine of thefclass described, the combination of aplurality of concentric rotary pistons mounted in movable relation to each other and each having piston wings on opposite sides of its axial center and in termediate the piston wings of the next adjacent piston, a cylinder encircling the pistons and provided with inlet and outlet ports, a pair of crank pins for each piston, means for connecting each piston with a pair of crank pins, adapted to permit the movement of the crank pins of each piston with respect to those ofthe other piston, a cam having three slots diverging from its central'portionoutward toward its peri hery and each adapted to engage a plura ity of crank pins successively, said cam being adapted to at all times engage crank pins of both pistons, each of said slots having a wallportion extending outward toward the periphery of the cam and adapted to engage an outwardly moving pin after an inwardly moving pin connected with such outwardly moving pin has entered another slot, the axis of said cam being in a different plane from the axis of the pistons and crank pins, and all of said elements being adapted to rotate in the same direction.

34. In a mechanism of the class described, the combination of a plurality of rotary pistons mounted in movable relation to each other and each having connected radial piston wings on opposite sides of its axial center and provided with piston chamber walls forming piston chambers into which the piston Wings extend, crank pin mechanism operatively connected with each piston and rotatable therewith, said crank pin mechanism comprising a plurality of crank pins, a plurality of cams mounted in engagement with the crank pin mechanism and between which cams the pistons are located, said piston chamber wall portions being provided with fluid inlet, and outlet ports, and means for opening and closing the inlet and outlet ports.

35. In a mechanism of the class described, the combination of a rotary piston-supporting hub, a plurality of rotary piston wings mounted upon the same central hub and extending radially from the hub, piston chamber walls forming piston chambers into which the piston wings extend, a second rotary member having radial wing portions located between said plurality of piston wings and in engagement with the piston chamber walls, crank pin mechanism opera tively connected with the hub on which such plurality of piston wings are mounted, a cam rotatably mounted and with said second rotary wing supporting member respectively in engagement with the crank pin mechanism and having a different axial center from that about which the piston wings are adapted to rotate, said piston chamber wall portions being provided with fluid inlet and outlet ports, and means for opening and closing the inlet and outlet ports.

HARRY IRl VIN GROMER. Witnesses LOUIS L. Konxon, JENNIE L. FIsKn.

Copies of this yeti-int may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. 0. 

